Laser gain medium and laser oscillator using the same

Abstract

A laser gain medium includes an optical medium configured to transmit a laser beam and having an incident face, a first face, a second face opposing to the first face; and gain media configured to amplify the laser beam while reflecting the laser beam. At least one of the gain media is joined on a first face of the optical medium as a first face gain medium, and at least one of the remaining gain media is joined on a second face of the optical medium as a second face gain medium. The laser beam is incident into the optical medium, and is amplified by the first face gain medium and the second face gain medium while being alternately reflected by the first face gain medium and the second face gain medium.

1. A laser gain medium comprising:
 an optical medium configured to transmit a laser beam and having an incident face, a first face, a second face opposing to said first face; and 
 a plurality of gain media pumped by a pumping light beam and configured to amplify the laser beam while reflecting the laser beam, wherein said plurality of gain media are formed of same optical material and doped with at least one active element, 
 wherein ones of said plurality of gain media are joined on a first face of said optical medium as first face gain media, and the remaining gain media are joined on a second face of said optical medium as second face gain media, 
 wherein the laser beam is amplified by said first face gain medium and said second face gain media while being alternately reflected by said first face gain media and said second face gain media, and 
 wherein at least one of (i) dope quantities of the active element into said plurality of gain media and (ii) thicknesses of said plurality of gain media in a direction perpendicular to the first or second face is adjusted such that an amount of heat generated by absorbing the pumping light beam is uniform over said plurality of gain media. 
 
     
     
       2. The laser gain medium according to  claim 1 , wherein an absorption factor of the pumping light beam of one of said first and second face gain media which is near to the incident face is smaller than that of the other gain medium which is distant from the incident face. 
     
     
       3. The laser gain medium according to  claim 1 , wherein said first face and said second face of said laser gain medium are cooled. 
     
     
       4. A laser system comprising:
 a laser gain medium; 
 a pumping light source configured to supply a pumping light beam; 
 a laser beam source configured to supply a laser beam; and 
 an input optical system configured to lead the laser beam on an optical path on which the pumping light beam propagates, 
 wherein said laser gain medium comprises: 
 an optical medium configured to transmit the laser beam and the pumping light beam and having an incident face, a first face, a second face opposing to said first face; and 
 a plurality of gain media pumped up by said pumping light source and configured to amplify the laser beam while reflecting the laser beam, wherein said plurality of gain media are formed of same optical material and doped with at least one active element, 
 wherein at least one of said plurality of gain media is joined on a first face of said optical medium as a first face gain medium, and at least one of the remaining gain media is joined on a second face of said optical medium as a second face gain medium, 
 wherein at least one of (i) dope quantities of the active element into said gain media and (ii) thicknesses of said gain media in a direction perpendicular to the first or second face is adjusted such that an amount of heat generated by absorbing the pumping light beam is uniform over said gain media, 
 wherein the pumping light beam is incident from said pumping light source into said optical medium through said incident face by said input optical system, and pumps up said first and second face gain media through the optical path while being alternately reflected by said first face gain medium and said second face gain medium, and 
 wherein the laser beam is propagated on the optical path and is amplified by said first face gain medium and said second face gain medium. 
 
     
     
       5. The laser system according to  claim 4 , wherein an absorption factor of the pumping light beam of one of said first and second face gain media which is near to the incident face is smaller than that of the other gain medium which is distant from the incident face. 
     
     
       6. The laser system according to  claim 4 , further comprising:
 a cooling unit configured to cool said first face and said second face of said laser gain medium.